The present invention relates to semiconductor production apparatus and pertains particularly to lead crimping apparatus for crimping leads of a header into a conducting relationship.
Many integrated circuits are plated at some stage during the production thereof. This plating usually takes place after the circuit has been packaged. The leads of the circuit must have a mutual continuity in order to be plated properly. This is accomplished by establishing a connection between the leads, preferably by crimping the leads into a contacting or conducting relationship.
Conventional integrated circuits are currently packaged in three distinctive configurations. These are round, flatpack, and dual in line (DIP). The round style is usually a glass metal package having multiple leads extending from one side thereof parallel to the axis of the body and in a substantially circular array. The leads on such round packages are usually bent or crimped into mutual contact before plating, in order to provide mutual continuity in the lead. These round packages are generally termed in the art, headers.
The crimping of the leads into an engaging or conducting relationship have been accomplished in the past by means of a conical die as shown in FIG. 5 which is moved axially into engagement with the leads of the header for camming them into contact. The die is usually reciprocally mounted on a machine and engages the leads of the respective headers as they pass thereby. One problem with such approach however, is that the leads of the header must be precisely in line with the die in order to be effective. Another problem is that when leads are bent outward from their normal position the die is ineffective and will tend to bend the particular lead further out of alignment.
In accordance with the prior art approach, as shown in FIG. 5, a semiconductor device 10, having been packaged in a substantially circular or rounded configuration, includes a plurality of leads 12, 14, 16 and 18 extending axially from one side parallel to the axis thereof and formed in a generally circular array. The process of crimping the leads into contact is carried out by means of a die 20 having a conical camming surface or portion 22 which axially engages the leads 12 through 18 for bending them into contenting engagement. The major problem with this approach is that a lead such as lead 18 may be bent outward from the remaining leads and not be engaged within the camming surface 22 of the die 20. Thus, this lead 18 is not crimped inward with the remaining leads and instead may be further bent outward. This arrangement results in many rejects and increases the cost of production.
Another problem with the prior art approach is that the speed of production in the crimping operation is limited, thereby further increasing the cost of production.
It is therefore desirable that some method and/or apparatus be available for quickly and effectively crimping the leads of semiconductor devices, and which is capable of properly crimping damaged or excessively outwardly bent semiconductor leads.